title: Importance of the proline-rich region for the regulatory function of RcsF, an outer membrane lipoprotein component of the Escherichia coli Rcs signal transduction system.
abstract: The outer membrane lipoprotein RcsF is an essential component of the Rcs phosphorelay signal transduction system in Escherichia coli. It senses stresses imposed on the cell envelope and conveys the information to histidine kinase RcsC in the cytoplasmic membrane. Mislocalization of RcsF to the periplasm, effected by fusing it to the periplasmic maltose-binding protein, or to the cytoplasmic membrane, brought about by changing the lipoprotein sorting signal, leads to high activation of the Rcs system, suggesting that RcsF functions as a ligand for RcsC in activating the system. Here, we focus on the proline-rich region (PRR) in the N-terminal half of RcsF, a region which also contains many basic amino acid residues. Deletion of the PRR in the mislocalized RcsF resulted in even higher activation of the Rcs system. The same deletion in wild-type RcsF lipoprotein that is correctly localized to the outer membrane, however, blocked activation of the system under stresses that normally should activate it. It is highly likely that the PRR plays an important role in the regulation of the function of RcsF in activating the Rcs system.
authors.affiliation: Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Umekawa
authors.affiliation: Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan.
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Miyagawa
authors.affiliation: Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan.
authors.forename: Daitetsu
authors.initials: D
authors.lastname: Kondo
authors.affiliation: Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsuoka
authors.affiliation: Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Matsumoto
authors.affiliation: Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hara
mesh_terms: D020816:Amino Acid Motifs; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008074:Lipoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism; D011392:Proline / Q000235:genetics* / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D008074:Lipoproteins; D009097:Multienzyme Complexes; C489728:rcsC protein, E coli; C078611:rcsF protein, E coli; D011392:Proline; D011494:Protein Kinases; D010749:Phosphoprotein Phosphatases